Receiving container body for object to be processed

ABSTRACT

The present invention includes: a box case having a size capable of containing an open type of cassette that can hold a plurality of first objects to be processed and capable of containing a plurality of second objects to be processed, the second objects to be processed being larger than the first objects to be processed; a supporting part provided at an inside wall surface of the box case, the supporting part being capable of supporting the second objects to be processed in a tier-like manner; an open-close lid provided at an opening part of the box case in a removable and attachable manner; and a positioning-engaging part provided at a bottom part of the box case in a removable and attachable manner. The open-close lid is capable of sealing the box case. The positioning-engaging part is capable of engaging with a positioning part provided at a lower surface of a bottom part of the cassette to position the cassette.

FIELD OF THE INVENTION

This invention relates to a containing case body for an object to beprocessed, which can contain an object to be processed such as asemiconductor wafer in an airtight manner, and to a processing systemusing the containing case body.

BACKGROUND ART

In general, in order to manufacture a semiconductor integrated circuitsuch as an IC or an LSI, various processes including a film-formingprocess, an oxidation-diffusion process, an etching process or the likeare repeatedly carried out to a semiconductor wafer. In order to conductthe various processes, the semiconductor wafer has to be transferredbetween respective processing units. In the case, as well known, in viewof improvement of yield, it is necessary to prevent that particlesand/or a natural oxide film may be formed and stuck on a surface of thesemiconductor wafer. Then, as requests for further integration andfurther miniaturization are increased, for the purpose of the wafertransfer, a containing case body tends to be used, which can contain aplurality of wafers and whose inside can be sealed. As this type ofcontaining case body, FOUP (registered trademark) is known in general(for example, JP Laid-Open publication No. 8-279546, JP Laid-Openpublication No. 9-306975 and JP Laid-Open publication No. 11-274267).The containing case body has a box case wherein one side end is formedinto an opening and the other side end is formed into a substantiallysemi-cylindrical shape. Supporting parts are provided on an inside wallsurface of the box case at substantially the same pitch in a tier-likemanner. A peripheral portion of a semiconductor wafer is placed on andsupported by each supporting part. Thus, semiconductor wafers can becontained at substantially the same pitch in a tier-like manner.Usually, about 25 or about 13 wafers can be contained in one containingcase body.

An open-close lid is attached at the opening of the box case in aremovable and attachable manner. When the open-close lid is attached,the box case can maintain an airtight state to a certain extent. Forexample, the inside of the box case is filled with an inert-gasatmosphere such as a clean air or an N₂ gas. At that time, the containedwafers hardly contact with an outside atmosphere.

A locking mechanism is provided in the open-close lid. By releasing thelocking mechanism, the open-close lid can be removed off from theopening.

Herein, the containing case body as described above, such as FOUP, isgenerally used for wafers having a lager diameter, for example wafershaving a diameter of 300 mm (12 inches). The containing case body suchas FOUP is not applied to wafers having a smaller diameter, for examplewafers having a diameter of 200 mm (8 inches) or a diameter of 150 mm (6inches). Conventionally, for the wafers having a smaller diameter, anopen type of cassette, which doesn't have a sealed structure, is used.The wafers are contained in the open type of cassette in a tier-likemanner while the wafers are exposed to an atmospheric air.

Under that situation, based on the requests for further integration andfurther miniaturization of an integrated circuit, for the purpose ofpreventing particle problems, it has been requested that the wafershaving a smaller diameter are transferred by using a hermetically-closedtype of containing case body.

In the case, it can be thought that different sizes of containing casebodies are used for respective wafer sizes. However, this may increasefacility cost. Thus, in order to avoid the problem, an assistant jig hasbeen proposed, which makes it possible to fix an open type of cassettefor wafers having a smaller diameter to the inside of a containing casebody for wafers having a larger diameter.

As the assistant jig, for example, a cassette adaptor AM-3004(registered trademark) made by Micro Tool co. is known. The assistantjig has a base 2 of a semi-elliptic shape, as shown in FIG. 15. Fourcolumns 4 stand up from peripheral portions of the base 2. Upper ends ofthe four columns 4 support a ceiling plate 6 of a semi-circular-arcshape, whose diameter is substantially the same as that of a 300 mmwafer. At substantially a center portion of the base 2, positioningprotrusions 8 are provided for positioning a cassette C for 200 mmwafers as wafers having a smaller diameter. The cassette C is adapted tobe positioned and fixed by the positioning protrusions 8.

Wheels 10 to be held having elasticity, for example made ofpoly-carbonate resin, are provided at peripheral portions of the base 2and the ceiling plate 6. The wheels 10 to be held are adapted to befitted in supporting parts of a containing case body for 300 mm wafers(not shown) which are originally provided for supporting peripheralportions of 300 mm wafers. Thus, the whole assistant jig is adapted tobe fixed in the containing case body for 300 mm wafers. That is, whenthe 300 mm wafers are to be contained, the containing case body for 300mm wafers is used in a state wherein the assistant jig is removed off.Then, when the 200 mm wafers are to be contained, the containing casebody for 300 mm wafers is used in a state wherein the assistant jig isfitted therein, so that the cassette C is fixed and used in theassistant jig. Thus, two kinds of wafers having different sizes can beselectively contained in a hermetically-sealed manner by means of onekind of containing case body.

However, the above assistant jig has the following problems. That is,the center of the 200 mm wafers when the 200 mm wafers are containedwith the assistant jig and the center of the 300 mm wafers when the 300mm wafers are contained without the assistant jig are located atsubstantially the same position in a horizontal plane. That is, when the200 mm wafers are contained, a larger space is generated between the 200mm wafers and the open-close lid. As a result, the 200 mm wafers mayconsiderably slide in the cassette C.

In addition, when the wheels 10 to be held are fitted into thesupporting parts for the 300 mm wafers, the supporting parts may bedamaged. If cracks or the like are formed in the supporting parts, whenthe supporting parts support the 300 mm wafers, the 300 mm wafers may bedamaged. Furthermore, if cracks or the like are formed in the supportingparts, the thin wheels 10 to be held may be broken and disenabled.

SUMMARY OF THE INVENTION

This invention is developed by focusing the aforementioned problems inorder to resolve them effectively. The object of this invention is toprovide a containing case body for an object to be processed and aprocessing system using the containing case body, wherein larger andsmaller objects to be processed having different diameters can beselectively contained, positions of the objects to be processed are notshifted while the objects to be processed are contained, and asupporting part for the larger object to be processed is not damaged.

This invention is a containing case body for an object to be processedcomprising: a box case having a size capable of containing an open typeof cassette that can hold a plurality of first objects to be processedand capable of containing a plurality of second objects to be processed,the second objects to be processed being larger than the first objectsto be processed; a supporting part provided at an inside wall surface ofthe box case, the supporting part being capable of supporting the secondobjects to be processed in a tier-like manner; an open-close lidprovided at an opening part of the box case in a removable andattachable manner; and a positioning-engaging part provided at a bottompart of the box case in a removable and attachable manner; wherein theopen-close lid is capable of sealing the box case; and thepositioning-engaging part is capable of engaging with a positioning partprovided at a lower surface of a bottom part of the cassette to positionthe cassette.

According to the invention, since the positioning-engaging part forpositioning the cassette is provided at a bottom part of the box case ina removable and attachable manner, when larger objects to be processed,for example of 300 mm diameter, are contained, peripheral portions ofthe larger objects to be processed can be supported by the supportingpart and the larger objects to be processed are contained in a tier-likemanner in a state wherein the positioning-engaging part is removed off.On the other hand, when smaller objects to be processed, for example of200 mm diameter, are contained, the open type of cassette is positionedand fixed in the box case by means of the positioning-engaging part in astate wherein the positioning-engaging part is attached, and the smallerobjects to be processed can be contained in the cassette. In addition,it can be prevented that the supporting part for the larger objects tobe processed is damaged.

In particular, it is preferable that a position of peripheral edges ofthe first objects to be processed on a side of the opening part when thecassette that holds the first objects to be processed is contained inthe box case and a position of peripheral edges of the second objects tobe processed on the side of the opening part when the second objects tobe processed are contained in the box case substantially coincide witheach other.

In addition, it is preferable that a first pop-out-preventing member isprovided on an inside of the open-close lid for preventing that thefirst objects to be processed pop out from the cassette when thecassette that holds the first objects to be processed is contained inthe box case.

In the case, it is preferable that the first pop-out-preventing memberis removable from and attachable to the open-close lid.

Alternatively, it is preferable that a second pop-out-preventing memberis provided on an inside of the open-close lid for preventing that thesecond objects to be processed pop out from the box case when the secondobjects to be processed are contained in the box case.

In the case too, it is preferable that the second pop-out-preventingmember is removable from and attachable to the open-close lid.

If a cassette base platform is contained at a bottom part of the boxcase in a removable and attachable manner, it is preferable that thepositioning-engaging part is provided on an upper surface of thecassette base platform.

In the case, preferably, a platform fixing jig is provided at aperipheral portion of the cassette base platform, the platform fixingjig is capable of protruding from and withdrawing into the peripheralportion, and the cassette base platform is adapted to be fixed in thebox case when the platform fixing jig is pressed to an inside wall ofthe box case.

For example, the platform fixing jig may be provided at each of threeperipheral portions of the cassette base platform.

Alternatively, the present invention is a containing case body for anobject to be processed comprising: a box case having a size capable ofcontaining an open type of cassette that can hold a plurality of objectsto be processed; an open-close lid provided at an opening part of thebox case in a removable and attachable manner; and apositioning-engaging part provided at a bottom part of the box case;wherein the open-close lid is capable of sealing the box case, and thepositioning-engaging part is capable of engaging with a positioning partprovided at a lower surface of a bottom part of the cassette to positionthe cassette.

In the case, it is preferable that a pop-out-preventing member isprovided on an inside of the open-close lid for preventing that theobjects to be processed pop out from the cassette when the cassette thatholds the objects to be processed is contained in the box case.

Alternatively, the present invention is a processing system comprising:a case-body conveying area in which a containing case body according toany of claims 1 to 11 can be conveyed; an object-to-be-processedconveying area that is filled with an inert-gas atmosphere or aclean-gas atmosphere; a division wall that divides the case-bodyconveying area and the object-to-be-processed conveying area; an openingformed at the division wall; a stage on which the containing case bodyis placed in such a manner that the opening part of the containing casebody faces the opening on a side of the case-body conveying area; a loadport provided in the case-body conveying area, capable of communicatingwith an outside area; a stocker provided in the case-body conveyingarea, by which the containing case body can be temporarily stocked; acase-body conveying mechanism that conveys the containing case bodybetween the load port, the stocker and the stage; an opening-closingmechanism that opens and closes the open-close lid of the containingcase body when the containing case body is placed on the stage; anobject-to-be-processed boat provided in the object-to-be-processedconveying area, corresponding to a size of an object to be processedcontained in the containing case body; a processing container providedin the object-to-be-processed conveying area, capable of conducting apredetermined thermal process to the object to be processed; a boatelevating mechanism that moves up and down the object-to-be-processedboat to convey the object-to-be-processed boat into and out from theprocessing container; and an object-to-be-processed conveying mechanismthat conveys the object to be processed between theobject-to-be-processed boat and the containing case body placed on thestage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a containing case body for anobject to be processed according to an embodiment of the presentinvention;

FIG. 2 is a perspective view showing a state of the containing case bodywherein larger objects to be processed are contained and an open-closelid is removed;

FIG. 3 is a perspective view showing a state of the containing case bodywherein a cassette containing smaller objects to be processed iscontained and the open-close lid is removed;

FIG. 4 is a perspective view showing a cassette containing smallerobjects to be processed;

FIG. 5 is a transversal sectional view showing the containing case bodyin a state wherein the cassette is contained therein;

FIG. 6 is a perspective view showing a cassette base platform providedwith a positioning-engaging part;

FIG. 7 is a view showing a state wherein a positioning member is fittedin the positioning-engaging part;

FIG. 8 is a view showing a pop-out-preventing member for a larger wafer;

FIG. 9 is a perspective view showing a portion of the pop-out-preventingmember shown in FIG. 8;

FIG. 10 is a view showing a pop-out-preventing member for a smallerwafer;

FIG. 11 is a perspective view showing a modified embodiment of acontaining case body of the present invention;

FIG. 12 is a schematic structural view showing an example of processingsystem of the present invention;

FIG. 13 is a perspective view showing a main part of the processingsystem;

FIG. 14 is a view showing an example of object-to-be-processed conveyingmechanism used in the processing system; and

FIG. 15 is a perspective view showing an example of conventionalassistant jig used for a containing case body.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, an embodiment of a containing case body for an object to beprocessed according to the present invention and a processing systemusing the containing case body is explained based on attached drawings.

FIG. 1 is a perspective view showing a containing case body for anobject to be processed according to the embodiment. FIG. 2 is aperspective view showing a state of the containing case body whereinlarger objects to be processed are contained and an open-close lid isremoved. FIG. 3 is a perspective view showing a state of the containingcase body wherein a cassette containing smaller objects to be processedis contained and the open-close lid is removed. FIG. 4 is a perspectiveview showing a cassette containing smaller objects to be processed. FIG.5 is a transversal sectional view showing the containing case body in astate wherein the cassette is contained therein. FIG. 6 is a perspectiveview showing a cassette base platform provided with apositioning-engaging part. FIG. 7 is a view showing a state wherein apositioning member is fitted in the positioning-engaging part.

As shown in FIGS. 1 and 2, the containing case body 12 has a box case 16wherein one side end thereof is formed as an opening part 14 and theother side end thereof is formed into a substantially semi-elliptic-poleshape. Supporting parts 18 are provided on an inside wall surface of thebox case 16 at substantially the same pitch in a tier-like manner. Forexample, each supporting part 18 is formed in a shelf-like orgroove-like shape. A peripheral portion of a semiconductor wafer W1 offor example 300 mm diameter as a larger object to be processed is placedon and supported by each supporting part 18. Thus, larger semiconductorwafers W1 can be contained at substantially the same pitch in atier-like manner. A knob 21 is provided at a ceiling part of the boxcase 16. The knob 21 is grasped when the whole box case 16 is held.Usually, about 25 or about 13 larger wafers W1 can be contained in onebox case 16.

A tetragonal hollow board-like open-close lid 20 is attached at theopening part 14 of the box case 16 in a removable and attachable manner,so that the inside of the box case 16 is maintained at an airtightstate. The inside of the box case 16 is adapted to be filled with anatmosphere of an inert gas such as an N₂ gas or a clean air. At thattime, the contained wafers W1 hardly contact with an outside atmosphere.

Two locking mechanisms 22 are provided in the open-close lid 20. Byreleasing the locking mechanisms 22, the open-close lid 20 can beremoved off from the opening part 14. Specifically, each lockingmechanism 22 has a disk-like locking plate 24, which is rotatablymounted at a substantially center of the open-close lid 20 in a verticaldirection. A longitudinal concave keyhole 26 is formed in the lockingplate 24. Protrusion pins 28 are respectively provided in an upwarddirection and in a downward direction with respect to the locking plate24, via a crank mechanism (not shown) that converts an arc movement intoa linear movement. Thus, when the locking plate 24 is rotatedreciprocally by substantially 90 degrees, the upper and lower protrusionpins 28 respectively move in the upward and downward directions.

At a locked state, as shown in FIG. 2, tip ends of the protrusion pins28 are adapted to be inserted in pinholes 30 at an upper edge portionand a lower edge portion defining the opening part 14 of the box case 6,and to engage with them (only pinholes 30 at the lower edge portion areshown in FIG. 2). Thus, at the locked state, the open-close lid 20 isadapted not to be removed off from the opening part 14. In addition, agroove portion 32 is formed at an inside of the opening part 14 in thevicinity of the lower edge portion.

Then, a pop-out-preventing member 34 is provided on an inside surface ofthe open-close lid 20, along a vertical direction thereof, forpreventing the wafers contained in the box case 16 from popping out (seeFIG. 3). The pop-out-preventing member 34 is a board-like member made ofa material such as PEEK (poly-ether-ether-ketone) or the like, which hasa great durability against halogen, halogen compounds, acid, alkali, andso on. In addition, a contact surface 36 of the pop-out-preventingmember 34 to the wafers is shaped into a curve surface havingsubstantially the same curvature as that of the larger wafers W1.

Herein, the pop-out-preventing member 34 may be made of a syntheticrubber or the like, that is, may have elasticity to some extent. Inaddition, arc grooves for containing peripheral edge portions of thewafers may be formed at the pop-out-preventing member 34.

As shown in FIGS. 3 to 6, a positioning-engaging part 38 for positioninga cassette C is provided at a bottom part of the box case 16 in aremovable and attachable manner. Specifically, as first, as shown inFIGS. 3 and 4, the cassette C can contain smaller objects to beprocessed, such as semiconductor wafers W2 having a diameter of 200 mm(8 inches), in a tier-like manner. In FIG. 4, the cassette C is shown ina state wherein a back surface of the cassette C contacts with a floor.The cassette C has a fully opened box shape. The cassette C is made of amaterial superior in chemical resistance and heat resistance, such asTeflon (registered trademark).

Supporting shelves 40 are arranged on right and left inside walls at thesame pitch in a tier-like manner. A peripheral edge portion of a smallerwafer W2 is placed on and supported by each supporting shelf 40. In thecase, for example about 25 smaller wafers W2 can be supported by the onecassette C. The knob 21 is omitted in FIG. 3.

Then, as shown in FIG. 4, a positioning member 42 protruding in asubstantially H-like shape is formed at a lower surface of the bottompart of the cassette C. The protruding positioning member 42 also has afunction as a reinforcing member for preventing deformation of thecassette C itself.

As shown in FIGS. 3, 5 and 6, in detail, the positioning-engaging part38 for positioning the cassette C is fixed on a cassette base platform44, which is mounted at the bottom part of the box case 16 in aremovable and attachable manner. The positioning-engaging part 38consists of two board members 46 and 48, which are arranged away fromeach other by a predetermined gap. The gap between the board members 46and 48 forms a groove 50 for fitting. As shown in FIG. 7, the length Lof the board members 46 and 48 is set a little smaller than the width L2of the positioning member 42 of the H-like shape on the lower surface atthe bottom part of the cassette C. On the other hand, the width L3 ofthe groove 50 is set a little larger than the thickness L4 of thepositioning member 42. When the positioning member 42 is fitted into thepositioning-engaging part 38 as shown in FIG. 7, the cassette C ispositioned and installed on the cassette base platform 44. The two boardmembers 46 and 48 may be formed by a single board member and the groove50 may be formed at a substantially center thereof. In addition, theboard members 46 and 48 may be attached to the cassette base platform 44in a position adjustable manner by means of a screw or the like.

The cassette base platform 44 has a size a little smaller than that ofthe bottom part of the box case 16, and is formed into a substantiallysemi-elliptic shape by PC (poly-carbonate) or the like. Threeplatform-fixing jigs 52, 54 and 56 are mounted in total at peripheralportions of the cassette base platform 44, that is, at both end portionson the side of the opening part 14 and at an inside position away fromthe opening part 14 (see FIG. 5).

Specifically, each platform-fixing jig 52, 54 or 56 has a fixed frame52A, 54A or 56A that is fixed to the cassette base platform 44. Eachfixed frame 52A, 54A or 56A is provided with an adjustable screw 52B,54B or 56B, which can protrude from and withdraw into the fixed frame ina horizontal direction. A pushing member 52C, 54C or 56C is attached toeach adjustable screw 52B, 54B or 56B. Each pushing member 52C, 54C or56C can move outside from the cassette base platform 44 by rotating eachadjustable screw 52B, 54B or 56B. The cassette base platform 44 is fixedin the box case 16 by pressing the pushing members 52C, 54C and 56Ctoward the inside wall of the box case 16.

Two guide long holes 58 are formed at each pushing member 52C, 54C or56C. A fixing screw 60 is inserted into each guide long hole 58. A lowerend of the fixing screw 60 can be screwed into the cassette baseplatform 44. Thus, under a state wherein the fixing screws 60 are loose,the respective pushing members 52C, 54C and 56C can move in therespective directions of the guide long holes 58. In addition, byfastening the fixing screws 60 under a state wherein the respectivepushing members 52C, 54C and 56C are pressed toward the inside wall ofthe box case 16, the cassette base platform 44 can be strongly andsurely fixed in the box case 16. In the case, a tip portion of thepushing member 56C located at the inside position is formed into a curvesurface corresponding to a curve wall surface of the box case 16.

In addition, as shown in FIG. 6, an engagement protrusion 62 thatprotrudes downward is provided on a lower surface of the cassette baseplatform 44 on a tip-end side (on the side of the opening part 14). Theengagement protrusion 62 is adapted to be fitted in the groove 32 (seeFIG. 2) provided at the bottom part of the box case 16.

Herein, an installation position of the positioning-engaging part 38 isset at such a position that tip-end side portions of the smaller wafersW2 contained in the cassette C contained in the box case 16substantially come in contact with the pop-out-preventing member 34.

Next, a case is explained wherein the larger wafers W1 and the smallerwafers W2 are selectively contained in the containing case body 12formed as the above.

At first, when the larger wafers W1 having a diameter of for example 300mm (12 inches) are contained in the containing case body 12, as shown inFIG. 2, the cassette base platform 44 and the like are not installed inthe box case 16. Under the state, peripheral portions of the largerwafers W1 are placed on the respective supporting parts 18 provided onthe inside wall of the box case 16. Thus, the wafers W1 are supported ina tier-like manner.

Then, the opening part 14 of the box case 16 is closed by the open-closelid 20. The open-close lid 20 is locked. At that time, thepop-out-preventing member 34 provided at the open-close lid 20substantially comes into contact with edge portions of the larger wafersW1. Thus, when the containing case body 12 is conveyed, it can beprevented that the larger wafers W1 move or shift in the containing casebody 12.

Next, a case is explained wherein the smaller wafers W2 having adiameter of for example 200 mm (8 inches) are contained in thecontaining case body 12. In the case, at first, the cassette baseplatform 44 as shown in FIG. 6 is installed at the bottom part of thebox case 16 that is in a vacant state. When the cassette base platform44 is installed, the cassette base platform 44 is contained at thebottom part in the box case 16. At that time, the engagement protrusion62 as shown in FIG. 6 is engaged with the groove 32 of the box casebottom (see FIG. 2). Then, the respective adjustable screws 52B, 54B and56B of the platform-fixing jigs 52, 54 and 56 are rotated in such amanner that the respective pushing members 52C, 54C and 56C moveoutward.

The respective tip ends of the pushing members 52C, 54C and 56C of theplatform-fixing jigs 52, 54 and 56 come in contact with the insidesurface of the box case 16, and are pressed toward the same strongly.Under that state, the respective fixing screws 60 are fastened so thatthe respective pushing members 52C, 54C and 56C are fixed. Thus, thecassette base platform 44 is fixed at the bottom part in the box case16. When the cassette base platform 44 is removed off, an operationreverse to the above may be carried out.

After the cassette base platform 44 is installed and fixed as describedabove, the open type of cassette C that can contain the wafers W2 havinga diameter of 200 mm is installed on the cassette base platform 44. Inthe case, the convex positioning member 42 (see FIG. 4) provided at thebottom part of the cassette C is positioned to and fitted in thepositioning-engagement part 38 (see FIG. 6) on the cassette baseplatform 44 (see FIG. 7).

Thus, the cassette C is installed at an appropriate position on thecassette base platform 44. In the cassette C, the smaller wafers W2having a diameter of 200 mm are placed in a tier-like manner, forexample. Thus, the smaller wafers W2 are contained and held in thecontaining case body 12.

In the case too, the opening part 14 of the box case 16 is closed by theopen-close lid 20. At that time, as shown in FIG. 5, thepop-out-preventing member 34 provided at the open-close lid 20substantially comes into contact with edge portions of the wafers W2 inthe cassette C. Thus, when the containing case body 12 is conveyed, itcan be prevented that the wafers W2 move or shift in the containing casebody 12 to pop out from the same.

As described above, since the cassette base platform 44 and the cassetteC are installed in and removed off from the box case 16, the largerwafers (the wafers W1 having a diameter of for example 300 mm) and thesmaller wafers (the wafers W2 having a diameter of for example 200 mm)can be selectively contained in the containing base body 12.

In addition, the cassette base platform 44 at which the cassette C isinstalled can be attached to or removed off only by handling theplatform-fixing jigs 52, 54 and 56. Thus, the attaching or removingoperation may be carried out easily.

In addition, when the cassette base platform 44 is installed in the boxcase 16, the supporting parts 18 (see FIG. 2) for supporting the largerwafers W1 are not used. Thus, the supporting parts 18 may not bedamaged.

Herein, in the above embodiment, the pop-out-preventing member 34consists of the board made of PEEK having the curve contact surface tothe wafers, but is not limited thereto. For example, a structure asshown in FIGS. 8 to 10 can be adopted. FIG. 8 is a view showing apop-out-preventing member for a larger wafer. FIG. 9 is a perspectiveview showing a portion of the pop-out-preventing member shown in FIG. 8.FIG. 10 is a view showing a pop-out-preventing member for a smallerwafer.

The pop-out-preventing member 64 for a larger wafer W1 as shown in FIGS.8 and 9 has a pair of elastic supporting arms 66, which can come incontact with peripheral edge portions of the wafer W1. The pair ofelastic supporting arms 66 may be made of PEEK(poly-ether-ether-ketone), for example. Each arm 66 can be bent, thatis, has elasticity to some extent. The pair of elastic supporting arms66 extends in a horizontal direction. The number of the pairscorresponds to the number of wafers W1 to be contained and the pairs arearranged at a predetermined pitch in a vertical (height) direction ofthe open-close lid 20. A containing concave portion 66A, which can pinchthe upper and lower surfaces of the wafer W1 to hold the same, is formedat the tip end of each elastic supporting arm 66. Thus, the peripheralportions of the wafers W1 are surely held. That is, the elasticsupporting arms 66 can prevent the larger wafers W1 from popping out.

The pop-out-preventing member 68 for a smaller wafer W2 as shown in FIG.10 has two thin elastic plate members 70A and 70B made of PEEK, forexample. Under a state wherein peripheral portions of the two elasticplate members 70A and 70B pinch the above elastic supporting arm 66, thetwo elastic plate members 70A and 70B are fixed to each other by meansof screws 72. As a result, the plate members 70A and 70B can prevent thesmaller wafer W2 from popping out. In the case, instead of the elasticsupporting arm 66, another member may be provided.

In addition, in the above embodiment, the wafer having a diameter of 300mm (12 inches) is used as a larger wafer W1, the wafer having a diameterof 200 mm (8 inches) is used as a smaller wafer W2. However, thisinvention is not limited thereto. A wafer having a diameter of forexample 150 mm (6 inches) may be used as a smaller wafer W2.

In addition, in the above embodiment, the positioning-engagement part 38is provided on the cassette base platform 44. However, this invention isnot limited thereto. The positioning-engagement part 38 may be directlyattached to and removed off from a bottom part of the box case 16,without using the cassette base platform 44. For example, thepositioning-engagement part 38 may be fixed to a bottom part of the boxcase 16 by means of screws or the like.

In addition, the containing case body 12 in the above embodiment canselectively contain the wafers W1 having a diameter of 300 mm and thewafers W2 having a diameter of 200 mm. However, this invention is notlimited thereto.

FIG. 11 is a perspective view showing a containing case body 80 that cancontain only smaller wafers W2 having a diameter of for example 200 mmtogether with the cassette C.

In the containing case body 80, it is sufficient that a box case 82 hasa size capable of containing the cassette C. Thus, the box case 82 isformed into a little smaller shape than the box case 16 as shown inFIGS. 2 and 3. In addition, of course, no supporting part for supportinga larger wafer W1 is provided at the box case 16.

In addition, the positioning-engagement part 38 doesn't have to beattachable and detachable. Thus, the cassette base platform 44 (see FIG.3) is not provided. That is, the positioning-engagement part 38 isdirectly fixed to a bottom part of the box case 82. Then, as describedabove, the cassette C is positioned and fixed by using thepositioning-engagement part 38.

On the other hand, the open-close lid 20 that closes an opening part ofthe box case 82 has the same dimensions as that shown in FIGS. 2 and 3.Thus, an outside mechanism for releasing the locking mechanism 22 (seeFIG. 2) of the open-close lid 20 of the containing case body 80 may bethe same as an outside mechanism for releasing the locking mechanism 22of the containing case body 12 shown in FIGS. 2 and 3. In FIG. 11, theknob is omitted.

As described above, according to the containing case body 80, thesmaller wafers W2 contained in the open type of cassette C can becontained in a hermetically sealed state.

Next, an example of processing system for conducting a predeterminedthermal process to the wafers W1 or W2 contained in the above containingcase body 12 or 80 is explained.

FIG. 12 is a schematic structural view showing an example of processingsystem of the present embodiment. FIG. 13 is a perspective view showinga main part of the processing system. FIG. 14 is a view showing anexample of object-to-be-processed conveying mechanism used in theprocessing system.

As shown in FIGS. 12 and 13, the whole processing system 90 for theobject to be processed is surrounded by a housing 92 made of stainlesssteel or the like. The inside of the housing 92 is divided by a divisionwall 98 into a case-body conveying area 94, in which the containing casebody 12 or 80 can be conveyed, and a wafer conveying area 96 as anobject-to-be-processed conveying area, in which the semiconductor wafersW1 or W2 as objects to be processed can be conveyed. A clean air flowsdownward in the case-body conveying area 94. The wafer conveying area 96is filled with an inert-gas atmosphere such as an N₂ gas or a clean-airatmosphere. The processing system 90 mainly consists of: a load port 100through which the containing case body 12 or 80 can be conveyed into orout from the system 90; a stocker 102 for temporarily storing thecontaining case body 12 or 80; a conveyance stage 106 at which thesemiconductor wafers W1 or W2 are conveyed between the containing casebody 12 or 80 and an object-to-be-processed boat 104; a processingcontainer 108 for conducting a predetermined thermal process to thesemiconductor wafers W held by the object-to-be-processed boat 104; anda lid opening-closing mechanism 110 provided on a side of the waferconveying area with respect to the conveyance stage 106.

At the load port 100, a box conveyance port 112 is formed in the housing92, and is always open. Outside the box conveyance port 112, an outsidestage 114 for placing the containing case body 12 or 80 conveyed fromthe outside is provided in an inward slidable manner.

On the other hand, in the stocker 102, for example two-row and two-stepshelves or the like may be provided for temporarily placing and stockingthe containing case body 12 or 80. In addition, at the conveyance stage106, one or more openings 116 are formed in the division wall 98dividing the both areas 94 and 96, the size of each opening 116 beingsubstantially the same as the opening part of the containing case body12 or 80. A stage 118 is provided horizontally on a side of thecase-body conveying area with respect to the opening 116. The containingcase body 12 or 80 placed on the stage 118 may be fixed by pressingtoward the division wall 98. In addition, at the opening 116, anopen-close door 120 that opens and closes the opening 116 is provided.Between the stage 118 and the load port 100, a case-body conveyingmechanism 122 having an elevating function is provided. Thus, thecontaining case body 12 or 80 can be conveyed freely between the loadport 100, the stocker 102, and the stage 106.

Then, just under the opening 116 on the side of the wafer conveyingarea, the opening-closing mechanism 110 for opening and closing theopen-close lid 20 of the containing case body 12 or 80 and theopen-close door 120 is provided. As the opening-closing mechanism 110,for example, an opening-closing mechanism disclosed in JP Laid-OpenPublication No. 8-279546 and an opening-closing mechanism disclosed inJP Laid-Open Publication No. 11-274267 may be used.

In the wafer conveying area 96, a boat elevating mechanism 124 thatmoves up and down the object-to-be-processed boat 104 such as a waferboat is provided. Then, an object-to-be-processed conveying mechanism126 having an arm 126A that can rotate, extend, and contract is providedbetween the boat elevating mechanism 124 and the conveyance stage 106.The object-to-be-processed conveying mechanism 126 can be moved up anddown by an up-down elevator 128. Thus, by causing the arm 126A of theobject-to-be-processed conveying mechanism 126 to rotate, extend and/orcontract and by moving up and/or down the object-to-be-processedconveying mechanism 126, the wafers W1 or W2 can be conveyed between thecontaining case body 12 or 80 on the stage 118 and theobject-to-be-processed boat 104.

The object-to-be-processed boat 104 is made of for example quartz, andis configured to support about 1 to 150 wafers at a predetermined pitchin a tier-like manner. Specifically, as the object-to-be-processed boat104, a boat for lager wafers having a diameter of for example 300 mm anda boat for smaller wafers having a diameter of for example 200 mm areprepared. Then, depending on the size of wafers to be processed, one ofthe boats is selectively used.

In addition, above one side portion in the wafer conveying area 96, thecylindrical processing container 108 made of quartz is arranged. Theprocessing container 108 is adapted to conduct a predetermined thermalprocess such as a film-forming process, an oxidation-diffusion processor the like to the many wafers W1 or W2 at a time. Then, the size of theprocessing container 108 is set to a size capable of containing thelarger wafers W1. Under the processing container 108, a cap 130 that canbe moved up and down by the boat elevating mechanism 124 is arranged.Above the cap 130, the object-to-be-processed boat 104 is placed. Then,by moving up the cap 130, the object-to-be-processed boat 104 can beloaded into the processing container 108 through a lower opening part ofthe processing container 108. The lower opening part of the processingcontainer 108 is adapted to be hermetically closed by the cap 130 whenthe object-to-be-processed boat 104 is loaded.

In addition, at the lower opening part of the processing container 108,a shutter 132 that can slide and close the lower opening part isprovided. The number of arms 126A of the object-to-be-processedconveying mechanism 126 is a plural number, for example five or so. Atthat time, five wafers can be conveyed at a time at the maximum. Herein,FIG. 14 shows an example of an arm 126A. FIG. 14(A) is a plan view ofthe arm, and FIG. 14(B) is a sectional view of the arm. A tip portion ofthe arm 126A has two step portions. The broader step portion is formedas a larger step portion 134A for holding the larger wafer W1. Thenarrower step portion is formed as a smaller step portion 134B forholding the smaller wafer W2.

Thus, the kind of arm 126A can handle both of the larger wafer W1 andthe smaller wafer W2. In addition, of course, the arm 126A may bereplaced depending on the size of a wafer.

According to the above processing system 90, whichever of the largerwafers W1 or the smaller wafers W2 are contained in the containing casebody 12 (only the smaller wafers W2 are contained in the containing casebody 80), the open-close lid 120 can be opened and closed by one kind ofopening-closing mechanism 110, the wafers W1 or W2 are placed on theobject-to-be-processed boat 104 corresponding to each size to undergothe predetermined thermal process in the processing container 108.

The structure of the above processing system 90 is only an example. Ofcourse, this invention is not limited thereto.

In the above, the semiconductor wafer is explained as an object to beprocessed. However, the object to be processed is not limited to thesemiconductor wafer. This invention can be also applied to a glasssubstrate, a LCD substrate or the like.

1. A containing case body for an object to be processed comprising: abox case having a size capable of containing an open type of cassettethat can hold a plurality of first objects to be processed and capableof containing a plurality of second objects to be processed, the secondobjects to be processed being larger than the first objects to beprocessed, a supporting part provided at an inside wall surface of thebox case, the supporting part being capable of supporting the secondobjects to be processed in a tier-like manner, an open-close lidprovided at an opening part of the box case in a removable andattachable manner, and a positioning-engaging part provided at a bottompart of the box case in a removable and attachable manner, wherein theopen-close lid is capable of sealing the box case, thepositioning-engaging part is capable of engaging with a positioningmember provided at a lower surface of a bottom part of the cassette toposition the cassette, and a position of peripheral edges of the firstobjects to be processed on a side of the opening part when the cassettethat holds the first objects to be processed is contained in the boxcase and a position of peripheral edges of the second objects to beprocessed on the side of the opening part when the second objects to beprocessed are contained in the box case substantially coincide with eachother.
 2. A containing case body for an object to be processed accordingto claim 1, wherein a first pop-out-preventing member is provided on aninside of the open-close lid for preventing that the first objects to beprocessed pop out from the cassette when the cassette that holds thefirst objects to be processed is contained in the box case.
 3. Acontaining case body for an object to be processed according to claim 2,wherein the first pop-out-preventing member is removable from andattachable to the open-close lid.
 4. A containing case body for anobject to be processed according to claim 1, wherein a secondpop-out-preventing member is provided on an inside of the open-close lidfor preventing that the second objects to be processed pop out from thebox case when the second objects to be processed are contained in thebox case.
 5. A containing case body for an object to be processedaccording to claim 4, wherein the second pop-out-preventing member isremovable from and attachable to the open-close lid.
 6. A containingcase body for an object to be processed according to claim 1, wherein acassette base platform is contained at a bottom part of the box case ina removable and attachable manner, and the positioning-engaging part isprovided on an upper surface of the cassette base platform.
 7. Acontaining case body for an object to be processed comprising: a boxcase having a size capable of containing an open type of cassette thatcan hold a plurality of first objects to be processed and capable ofcontaining a plurality of second objects to be processed, the secondobjects to be processed being larger than the first objects to beprocessed, a supporting part provided at an inside wall surface of thebox case, the supporting part being capable of supporting the secondobjects to be processed in a tier-like manner, an open-close lidprovided at an opening part of the box case in a removable andattachable manner, and a positioning-engaging part provided at a bottompart of the box case in a removable and attachable manner, wherein theopen-close lid is capable of sealing the box case, thepositioning-engaging part is capable of engaging with a positioningmember provided at a lower surface of a bottom part of the cassette toposition the cassette, a cassette base platform is contained at a bottompart of the box case in a removable and attachable manner, thepositioning-engaging part is provided on an upper surface of thecassette base platform, a platform fixing jig is provided at aperipheral portion of the cassette base platform, the platform fixingjig is capable of protruding from and withdrawing into the peripheralportion, and the cassette base platform is adapted to be fixed in thebox case when the platform fixing jig is pressed to an inside wall ofthe box case.
 8. A containing case body for an object to be processedaccording to claim 7, wherein the platform fixing jig is provided ateach of three peripheral portions of the cassette base platform.
 9. Aprocessing system comprising a containing case body according to claim1, a case-body conveying area in which the containing case body can beconveyed, an object-to-be-processed conveying area that is filled withan inert-gas atmosphere or a clean-gas atmosphere, a division wall thatdivides the case-body conveying area and the object-to-be-processedconveying area, an opening formed at the division wall, a stage on whichthe containing case body is placed in such a manner that the openingpart of the containing case body faces the opening on a side of thecase-body conveying area, a load port provided in the case-bodyconveying area, capable of communicating with an outside area, a stockerprovided in the case-body conveying area, by which the containing casebody can be temporarily stocked, a case-body conveying mechanism thatconveys the containing case body between the load port, the stocker andthe stage, an opening-closing mechanism that opens and closes theopen-close lid of the containing case body when the containing case bodyis placed on the stage, an object-to-be-processed boat provided in theobject-to-be-processed conveying area, corresponding to a size of anobject to be processed contained in the containing case body, aprocessing container provided in the object-to-be-processed conveyingarea, capable of conducting a predetermined thermal process to theobject to be processed, a boat elevating mechanism that moves up anddown the object-to-be-processed boat to convey theobject-to-be-processed boat into and out from the processing container,and an object-to-be-processed conveying mechanism that conveys theobject to be processed between the object-to-be-processed boat and thecontaining case body placed on the stage.